I have a pure E4 application with the DnDAddon installed, so I can drag ViewParts with the mouse and change the layout of the applicatino interactively.
However, those thin "Ghost frames" (Sorry, I don't know the correct English term) that appear during a drag & drop operaton are hardly visible, so the users have difficulty seeing where the ViewPart will move to if the release the mouse-button.

This was much different in E3 applications.

Any pointer about how to change the appearance of those preview-lines would be much appreciated!